After Reggie gives an inspiring talk to a group of African-American youths at a local church, he is accused of a terrible hit and run accident by a couple of white youths with whom he had previously had an unpleasant encounter. Led away from NASA in handcuffs, he fears that his long dream of making it to space may be over for good as he watches the newly appointed Head of the Astronaut Office, Bull, ready a replacement for the mission. Although this is devastating to Reggie he is determined to clear his name and reclaim his position as Mission Commander.

While on a Shuttle mission with Jack Riles, for the new Space Station, Astronaut Sam Blakes wife is rushed to the hospital suffering from complications in her pregnancy. Bull is prepared to scrap the mission until, unexpectedly, Kathy dies. The decision is then made not to tell Sam and to continue with the last 2 days of the mission, even though Sams tiny baby daughter is fighting for her life. Riles soon learns the truth and initially refuses to go along with the deception, but relents after being ordered to. At home Bull and Ellen work together to break the news to Sam's other children and to look after them until their father returns from space.

With many prominent politicians and military people expected, there are hectic preparations underway for the celebration at NASA to be coupled with the arrival of Space Shuttle Atlantis from its latest mission. With everything going on, the last thing that base personnel need to contend with is a bomb threat. Bull is drawn into the investigation with only a few hours to find out if there is a bomb, where it could be and to disarm it before Atlantis lands. Also, Jack and Zeke are participating in an experiment testing the design of a newer lighter space suit. Jack, in a careless moment, fails to monitor Zeke in the pressurized tank. When Zeke collapses, Jack rushes, unprotected, into harms way to rescue Zeke - only to collapse himself.

An elated Reggie Warren has finally realized his dream and has made it into space on a routine mission of a construction EVA and scientific reasearch. All does not go well for long, however, turning his dream into a nightmare. While Reggie and Japanese astronaut Hiro Furukawa are outside the orbiter on an extended EVA there is an accidental release of mercury sulphur gas during one of the experiments inside of the shuttle. On their return inside they find the 2 scientists disoriented, sweating and confused as to what has happened. Reggie must muster all of his faculties to return the Shuttle back to earth and save himself and his crew as he realizes that he too has been exposed to the toxic gas.

After 2 years in space, a satellite is returned to earth and is found to have a mysterious substance on its outside surface. Tamara is called in to help in the investigation until Keith Mason and his team from Ames Research push her aside and exclude her from valuable information. Tamara has, however, reserved a sample and does her own research, enlisting D.B.'s help, and discovers that amazingly enough, the substance contains living cells. Mason finds out what she has done and takes steps to bar her completely from further involvement. For the first time Tamara begins to realize that there is more going on than she ever suspected and realizes that she will likely never find out the truth behind what she has found. Meanwhile, while preparing for his first Shuttle mission, Reggie makes the (well-intentioned) mistake of allowing a friend to sleep at his place for a few days. The distraction of a loud houseguest and the stress caused by lack of sleep have him making careless mistak

While on a mission to repair a corporate communications satellite, the shuttle crew encounters a Soviet spacecraft that turns out to have been a secret attempt to send a manned mission to the moon - launched, and lost, over 30 years ago - that, had it succeeded, would have reached the moon before the United States.

Zeke is upset by the news that his brother Curt has become involved with his ex-girlfriend. Inevitably when he meets up with Natalie he discovers that they are still attracted to one another and secretly they begin to see each other again. Jack receives a surprise from an old girlfriend - a son that he never knew he had! Joanna had kept her pregnancy secret knowing that he did not want children, but a job that will take her to Bosnia has caused her to decide that the best place for Noah is with his father - Jack.

As a former teacher, astronaut candidate Peter is elected to guide a group of grade students around Kennedy Space Center, prior to the launch of Space shuttle Columbia. One of the students is an annoying young boy, named Tony, who, after being reprimanded by Peter, manages to slip away from the group to get a closer view of the launch area. The countdown is then temporarily suspended while a search is carried out to find the child.

With the position of Space Station Commander up for grabs, Bull lobbies hard for the chance. Unfortunately he is up against a media savvy opponant who has all the right connections. Reggie has been nominated to show around a Colonel from the National Space Developement of Japan, which proves difficult when languange and cultural differences arise. Ladies man Jack Riles is stalked by an ardent female fan who has plans to destroy his life one piece at a time before destroying him.

Bull publicly locks horns with D.B.'s father, former astronaut turned congressman, when, during a visit to NASA, it is revealed that he has plans to shut down the manned space program. Also, Reggie, having waited years for another opportunity, desperately tries to find out if there is any truth behind a rumor that has him scheduled to pilot the next shuttle mission.

The personal problems created by gaining custody of her child, begin to manifest themselves during a flight simulation, putting Caitlins space launch in jeopardy. Once she makes it to space she experiences a collapsed lung which requires Tamara to perform emergency surgery while in orbit.

Reggie blames himself as Barbara remains unconscious in the hospital following an accident. Zekes friend Jimmy is killed during a foolish game of duel when a cocky young pilot challenges him during training exercises. When Zeke learns that the young pilot is a friend that he served with in the Gulf, he remains silent about his involvement, honoring a debt that he believes he owes to his fellow pilot. All the while D.B. searches for the truth as to what really happened to Jimmy.

A planned shuttle launch is scrubbed when it is learned that a Russian satellite, carrying an unusually large nuclear reactor, is out of control and in a slow orbiting descent that will see it crash somewhere along the eastern seaboard of the United States. Making use of the already prepped-for-launch shuttle, Americans and Russians team up to capture the satellite and bring it back to earth aboard the shuttle.

A planned shuttle launch is scrubbed when it is learned that a Russian satellite, carrying an unusually large nuclear reactor, is out of control and in a slow orbiting descent that will see it crash somewhere along the eastern seaboard of the United States. Making use of the already prepped-for-launch shuttle, Americans and Russians team up to capture the satellite and bring it back to earth aboard the shuttle.